On Sat, Jun 13, 2009 at 8:13 AM, Martin
Makundi<martin.maku...@koodaripalvelut.com> wrote:
> Hi!
>
> Yes.. this is true but not ideally consistent. More consistent would be
>
> DropDownChoice<? extends BaseClass> dropDown = new DropDownChoice<?
> extends BaseClass>("id");
You can't instantiate with a wildcard type. That's not allowed by the
Java language.
>
> in such a way that dropDown.getChoiceRenderer() would be automatically
> of type <BaseClass>.
>
> One solution would be to change the signature of DropDownChoice (and
> selectchoices ...):
>
> public class DropDownChoice<T> extends .... into
>
> public class DropDownChoice<T, S extends T> extends .... in such a manner that
>
> DropDownChoice<? extends BaseClass=T> dropDown = new DropDownChoice<?
> extends BaseClass=T>("id");
> and
>
> DropDownChoice.getChoiceRenderer() : S
>
> That would work... both ways?
I, for one, would be -1 to such a change (non-binding of course). Why
do you need the ChoiceRenderer to support a specific subtype of
BaseClass? If you have a ChoiceRenderer<BaseClass> (which is what you
get if you declare your variable as I suggest), you can pass it any
type that extends BaseClass. You do not need to declare your
variables with the wildcard. What consistency are you looking for?
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